Blue Hill Yogurt was born in the kitchens of Blue Hill New York and Blue Hill at Stone Barns, where my brother Dan Barber and his culinary team have been experimenting with grass-fed milk yogurt for years," says David Barber, president and co-owner.

After the tour, Obama and the diplomats' spouses will attend a luncheon at the acclaimed Blue Hill at Stone Barns restaurant, where they will dine on ingredients they observed during their tour of the farm.

In "The Mouth That Matters" (page 80), chef-owner Dan Barber of Blue Hill in New York City and Blue Hill at Stone Barns gives a behind-the-scenes account of how restaurants really react when there's a food critic in the house.